WinAPI: CreatePen 建立画笔

//声明:
CreatePen(
  Style, Width: Integer; {样式与笔宽}
  Color: COLORREF        {颜色}
): HPEN;                 {返回笔句柄}

//Style 参数可选值:
PS_SOLID       = 0; {实线}
PS_DASH        = 1; {段线; 要求笔宽<=1}
PS_DOT         = 2; {点线; 要求笔宽<=1}
PS_DASHDOT     = 3; {线、点; 要求笔宽<=1}
PS_DASHDOTDOT  = 4; {线、点、点; 要求笔宽<=1}
PS_NULL        = 5; {不可见}
PS_INSIDEFRAME = 6; {实线; 但笔宽是向里扩展}


//举例:
procedure TForm1.FormPaint(Sender: TObject);
var
  PenStyle: Integer; {Pen 样式}
  PenHandle: HPEN;   {Pen 句柄}
begin
  PenStyle := RadioGroup1.ItemIndex;

  PenHandle := CreatePen(PenStyle, 1, clRed);
  Canvas.Pen.Handle := PenHandle;
  Rectangle(Canvas.Handle, 20, 20, 96,160);
  DeleteObject(PenHandle);
end;

procedure TForm1.RadioGroup1Click(Sender: TObject);
begin
  Self.Refresh;
end;


//效果图:

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//测试 PS_SOLID 与 PS_INSIDEFRAME 的区别
procedure TForm1.FormPaint(Sender: TObject);
var
  PenHandle: HPEN;
begin
  PenHandle := CreatePen(PS_SOLID, 20, clRed);
  Canvas.Pen.Handle := PenHandle;
  Rectangle(Canvas.Handle, 20, 20, 96,132);

  PenHandle := CreatePen(PS_INSIDEFRAME, 20, clRed);
  Canvas.Pen.Handle := PenHandle;
  Rectangle(Canvas.Handle, 120, 20, 196,132);

  PenHandle := CreatePen(PS_SOLID, 1, clRed);
  Canvas.Pen.Handle := PenHandle;
  Rectangle(Canvas.Handle, 220, 20, 296,132);

  DeleteObject(PenHandle);
end;


//效果图:

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